This tool is still in development, but
feedback
is welcome while I work on it. If you only use one filter, use the
grayscale filter which will not only point out potential problem areas,
but will also let you see more clearly which areas the filter is unable to process.

Please indicate a resource to be viewed, and a color filter
to be applied to that resource:

Other Options...

Disable Image Filtering
(recomendation: do not check this box initially)

Image filtering takes more time than HTML or CSS filtering.
If you use images to convey information or to present navigational
elements, then you should filter images the first time you check
your web page. After that first check, you may wish to save time
by disabling image filtering unless you have made a change to the
images (or their background/foreground). Checking this box will
give an amazing speed increase.

(Not relevant if all image filtering has beeen disabled above.)
At this time, we only filter GIF images. This means that non-GIF
images must first be transated into GIF format before they can be
processed. This results in a loss of image quality in some cases,
and a performance hit in most cases. You may want to compromise
on performance by only disabling the filtering of non-GIF images.
Checking this box will give a noticable speed increase.

Disable Stylesheets
(recomendation: do not check this box)

Our CSS filtering is not perfect, but it is much better
than our filtering of client-side scripts. If your page is one
of the problematic exceptions, create a version which does not
use CSS (or which uses simpler CSS) to demonstrate equivilant
web page coloration. Run that page through our filter.

Supress Filtering of Broken CSS Colors
(recomendation: do not check this box initially)

Some CSS authors incorrectly leave the '#' off of their #RRGGBB color
values. To see how color blind users probably see the page, allow the
utility to attempt to filter these constructs. To hilight these errors,
use one of the 'coverage' modes and check the box to supress filtering
of this incorrect syntax.

Our Logo

If your page meets the following criteria, please feel free to use this logo on your web site (available in
gif
and
png
formats). You may use the logo from this server or a local copy,
but should include the following HREF and ALT text in your markup:<a href="http://colorfilter.wickline.org/colorblind/filter/button"><img alt="See your web site through colorblind eyes with the colorblind web page filter." src="http://colorfilter.wickline.org/colorfilter_button.gif" width="88" height="31"></a>

or all text foreground/background colors are transformed to the coverage color
(because your markup sets both foreground and background colors to ensure adequate contrast)

The logo is based on an image from the
Color Vision Testing Made Easy
screening test developed by
Terrace L. Waggoner, O.D.
and is now used with his permission. I confess that the colorfilter logo
was originally developed without his permission before I knew of
the boat's origin. Fortunately, Dr. Waggoner was very understanding.